From a5dc381b4c987d933f1207035e275cdc24669de6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A5rten=20Nordheim?= <marten.nordheim@qt.io>
Date: Thu, 29 Apr 2021 12:36:12 +0200
Subject: [PATCH] QByteArrayView: add compare

There was previously no way to compare QByteArrayView to with another
QByteArrayView case-insensitively without allocating memory.

[ChangeLog][QtCore][QByteArrayView] Added compare(), enabling case
sensitive and insensitive comparison with other QByteArrayViews.

Change-Id: I7582cc414563ddbde26da35a568421edcc649f93
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/text/qbytearrayview.h                 |  8 ++++++++
 src/corelib/text/qbytearrayview.qdoc              | 12 ++++++++++++
 .../text/qbytearrayview/tst_qbytearrayview.cpp    | 15 +++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/src/corelib/text/qbytearrayview.h b/src/corelib/text/qbytearrayview.h
index 367fdb58b2..9d35e21415 100644
--- a/src/corelib/text/qbytearrayview.h
+++ b/src/corelib/text/qbytearrayview.h
@@ -270,6 +270,8 @@ public:
     [[nodiscard]] qsizetype count(char ch) const noexcept
     { return QtPrivate::count(*this, QByteArrayView(&ch, 1)); }
 
+    inline int compare(QByteArrayView a, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+
     //
     // STL compatibility API:
     //
@@ -320,6 +322,12 @@ template<typename QByteArrayLike,
 [[nodiscard]] inline QByteArrayView qToByteArrayViewIgnoringNull(const QByteArrayLike &b) noexcept
 { return QByteArrayView(b.data(), b.size()); }
 
+inline int QByteArrayView::compare(QByteArrayView a, Qt::CaseSensitivity cs) const noexcept
+{
+    return cs == Qt::CaseSensitive ? QtPrivate::compareMemory(*this, a) :
+                                     qstrnicmp(data(), size(), a.data(), a.size());
+}
+
 #if QT_DEPRECATED_SINCE(6, 0)
 QT_DEPRECATED_VERSION_X_6_0("Use the QByteArrayView overload.")
 inline quint16 qChecksum(const char *s, qsizetype len,
diff --git a/src/corelib/text/qbytearrayview.qdoc b/src/corelib/text/qbytearrayview.qdoc
index 91048c5dad..30d8d47685 100644
--- a/src/corelib/text/qbytearrayview.qdoc
+++ b/src/corelib/text/qbytearrayview.qdoc
@@ -353,6 +353,18 @@
     \sa data(), begin(), end()
 */
 
+/*!
+    \fn int QByteArrayView::compare(QByteArrayView bv, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
+    \since 6.2
+
+    Returns an integer less than, equal to, or greater than zero depending on
+    whether this QByteArrayView sorts before, at the same position as, or after
+    the QByteArrayView \a bv. The comparison is performed according to case
+    sensitivity \a cs.
+
+    \sa operator==()
+*/
+
 /*!
     \fn QByteArrayView::const_iterator QByteArrayView::begin() const
 
diff --git a/tests/auto/corelib/text/qbytearrayview/tst_qbytearrayview.cpp b/tests/auto/corelib/text/qbytearrayview/tst_qbytearrayview.cpp
index 35f883068d..d65731fdbd 100644
--- a/tests/auto/corelib/text/qbytearrayview/tst_qbytearrayview.cpp
+++ b/tests/auto/corelib/text/qbytearrayview/tst_qbytearrayview.cpp
@@ -193,6 +193,7 @@ private slots:
     }
 
     void comparison() const;
+    void compare() const;
 
 private:
     template <typename Data>
@@ -635,5 +636,19 @@ void tst_QByteArrayView::comparison() const
     QVERIFY(bb > aa);
 }
 
+void tst_QByteArrayView::compare() const
+{
+    QByteArrayView alpha = "original";
+
+    QVERIFY(alpha.compare("original", Qt::CaseSensitive) == 0);
+    QVERIFY(alpha.compare("Original", Qt::CaseSensitive) > 0);
+    QVERIFY(alpha.compare("Original", Qt::CaseInsensitive) == 0);
+    QByteArrayView beta = "unoriginal";
+    QVERIFY(alpha.compare(beta, Qt::CaseInsensitive) < 0);
+    beta = "Unoriginal";
+    QVERIFY(alpha.compare(beta, Qt::CaseInsensitive) < 0);
+    QVERIFY(alpha.compare(beta, Qt::CaseSensitive) > 0);
+}
+
 QTEST_APPLESS_MAIN(tst_QByteArrayView)
 #include "tst_qbytearrayview.moc"